Capsule technology continues to be subject to development and improvements. In its basic form, standard containers for pharmaceuticals or other powdered, granular or liquid substances (generally referred to as telescope-type, multi-part, or two-piece capsules) include a tubular-shaped and/or cylindrically-shaped first part, namely a cap part, which is closed on one end and open on the other opposite end. A tightly fitting second part of similar shape, namely the body part, is of smaller diameter than the cap part and is typically telescopically engaged therein to form the overall dosage form or two-piece capsule. Similar capsule technology may be used to generate multi-compartment capsules.
The vast majority of capsules are intended for oral delivery, and may comprise single or multi-compartment capsules for delivery of one or more active materials by ingestion of such capsules via the oral route. These include capsules for delayed and target release in specific delivery areas of the gastro intestinal tract typically by improving the acid resistance of the shells of the capsules. A number of ways for improving acid resistance of capsules have been described in the literature.
Examples of single compartment hard capsules are ones as described in EP0861061B1 and sold by Capsugel® under the brand Coni-Snap®. Such can be made of gelatin or specialty polymers like HPMC (like Vcaps®, Vcaps® Plus, DRcaps®) or pullulan (like Plantcaps®), the compositions further being described and exemplified in EP0946637B1, EP105786281, EP2078042A1, EP2480218A1, EP120469981, and W02012/095746A2 respectively.
Examples of multi-compartment capsules include the capsule-in-capsule executions described in EP1301178B1, wherein an inner capsule containing a substance is contained within an outer (larger) capsule further comprising a substance which can be the same or different from the substance contained in the inner capsule.
A different form of delivery, to classic oral administration, is that of sprinkle applications (particularly suitable for some delivery products or geriatric/pediatric subjects with swallowing difficulties). In such case the capsule is designed to be more easily openable compared to dosage forms designed for oral delivery by reducing the locking force generated by the engaged cap and body parts of the capsule, an example is described in EP2994114A1.
In this latter form of delivery in particular, it is desirable to on the one hand ensure that such capsules are not accidentally swallowed, and on the other hand ensure that opening of the capsule is further improved whilst maintaining an attractive overall aesthetic impact in the eyes of a subject.
A need therefore exists to develop a capsule and methods of making that provide this additional functionality particularly desirable in the sprinkle-type form of delivery.